use strict;
use Test::More tests => 3;
use Graph;
my $g = Graph->new;
ok( !$g->has_vertices() );
$g->add_vertex("a");
ok( $g->has_vertices() );
$g->add_vertex("b");
ok( $g->has_vertices() );
use strict;
use Test::More tests => 3;
use Graph;
my $g = Graph->new;
ok( !$g->has_vertices() );
$g->add_vertex("a");
ok( $g->has_vertices() );
$g->add_vertex("b");
ok( $g->has_vertices() );